Pages 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 13194 result(s) returned

Fe, C 0.07, Mn 2.3 (wt%) steel, carburised at 950°C
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. The carbon gradient can be seen in the changing shade of the sample from left to righ
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Fe, C 0.07, Mn 2.3 (wt%) steel, carburised at 950°C
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. The carbon gradient can be seen in the changing shade of the sample from left to righ
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Strain-induced birefringence in a notched polycarbonate bar
The colours in the image are the result of birefringence and relate to the strain-induced alignment of the polycarbonate molecules. Because the specimen is below the glass transition temperature of PC (145 °C), the material will relax when the stress is removed and there will be no residual alignment. The colours reveal the pattern of stress concentration around the notch.
Author(s): J A Curran, Department of Materials Science and Me

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Fe, C 0.07, Mn 2.3 (wt%) steel, carburised at 950°C
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. The carbon gradient can be seen in the changing shade of the sample from left to righ
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Shear bands in stressed polycarbonate
Yielding in glassy polymers often proceeds by a small sheared region propagating through the material. These patterns can be used in the stress analysis of fracture processes. In addition, the colours in the image are the result of birefringence and relate to the strain-induced alignment of the polycarbonate molecules. Because the specimen is below the glass transition temperature of PC (145 °C), the material will relax when the stress is removed and there will be no residual alignment.
Author(s): J A Curran, Department of Materials Science and Me

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Fe, C 0.2 (wt%) steel, case hardened
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. This micrograph has been taken from the bulk of the sample, showing that carbon does
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Fe, C 0.07, Mn 2.3 (wt%) steel, carburised at 950°C
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. The carbon gradient can be seen in the changing shade of the sample from left to righ
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Fe, C 0.15 (wt%) steel, carburised
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. This micrograph has been taken from the bulk of the sample, showing that carbon does
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Injection-moulded polystyrene (PS) case
The colours in the image are the result of birefringence and relate to the residual strain in the polystyrene. The pattern of strain is indicative of the flow of material during the injection process and it highlights the injection point (known as a 'sprue') which can also be identified by a small lump on the surface; the molecular alignment is greatest near this point. Towards the edges of the ruler and along its length, the material becomes more relaxed and as the molecular alignment falls, th
Author(s): J A Curran, Department of Materials Science and Me

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Birefringence in a film of polypropylene
The colours in the image are the result of birefringence and relate to the residual stress in the film, following the biaxial stretching process. The uniformity of the colour (with contrast only where an additional thickness of film exists or where wrinkling has resulted in a different apparent thickness) is indicative of both a uniform film thickness and of the uniformity of the drawing process used to make the film. Note that unlike polyethylene, the film has not been permanently strained in t
Author(s): J A Curran, Department of Materials Science and Me

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Fe, C 0.15 (wt%) steel, carburised
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. The carbon gradient can be seen in the changing shade of the sample from left to righ
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Fe, C 0.2 (wt%) steel, case hardened
After initial casting of this steel it was subject to a process known as carburisation. The metal is heated to above the ferrite-austenite transition in a carbon atmosphere. This establishes a concentration gradient and hence carbon diffuses into the steel. Usually the steel is then hardened by quenching. This produces what is known as a case hardened steel - with a hard surface (case) surrounding a tough core. This micrograph has been taken from the bulk of the sample, showing that carbon does
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Strain-induced birefringence in a polycarbonate bar
The colours in the image are the result of birefringence and relate to the strain-induced alignment of the polycarbonate molecules. Because the specimen is below the glass transition temperature of PC (145 °C), the material will relax when the stress is removed and there will be no residual alignment. The colours reveal the pattern of stress concentration around the points of contact with the rig, with a neutral axis along the centre and opposite values of birefringence on either side.
Author(s): J A Curran, Department of Materials Science and Me

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Glass transition: deformation of a rubber ball near Tg. Bounce close up
Part of a series of videos showing the glass transition in polymers, and the resulting change in energy dissipation on impact: Close up video at one tenth actual speed of ball bouncing near Tg. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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Glass transition: energy dissipation as rubber ball bounces at −70 °C
Part of a series of videos showing the glass transition in polymers, and the resulting change in energy dissipation on impact: Video at one tenth actual speed of a rubber ball bouncing at -70° C (close to Tg), showing that nearly all the energy is dissipated, and the ball barely bounces at all. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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Glass transition: energy dissipation as rubber ball bounces at −50 °C
Part of a series of videos showing the glass transition in polymers, and the resulting change in energy dissipation on impact: Video at one tenth actual speed of a rubber ball bouncing at -50° C (just above Tg), showing that more of the elastic strain energy is dissipated, and the ball does not bounce as high. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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Anisotropic dielectric permittivity: tetragonal-cubic phase transition in barium titanate
A thin section of barium titanate is viewed between crossed-polars, Initially, the sample is below the transition temperature, and since the domains of the anisotropic tetragonal phase exhibit birefringence, it is brightly coloured when viewed between crossed-polars. When the sample reaches the transition temperature, the isotropic cubic phase forms, which appears black. From TLP: Introduction to Anisotropy, http://www.msm.cam.ac.uk/doitpoms/tlplib/anisotropy/dielectric.php
Author(s): DoITPoMS, University of Cambridge

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Glass transition: energy dissipation as rubber ball bounces at 25 °C
Part of a series of videos showing the glass transition in polymers, and the resulting change in energy dissipation on impact: Video at one tenth actual speed of a rubber ball bouncing at 25° C (well above Tg), showing that the ball loses little energy as it bounces. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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Glass transition: energy dissipation as rubber ball bounces at −190 °C
Part of a series of videos showing the glass transition in polymers, and the resulting change in energy dissipation on impact: Video at one tenth actual speed of a rubber ball bouncing at −190 ° C (well below Tg), showing that as the temperature is reduced below Tg, there is not enough energy for conformational changes to occur, and the ball becomes glassy. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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Glass transition: plastic deformation in a ball of putty under its own weight
Silly putty exhibits a glass transition. A ball of putty is left at rest at room temperature. It slowly deforms plastically under its own weight. From TLP: The Glass Transition in Polymers, http://www.msm.cam.ac.uk/doitpoms/tlplib/glass-transition/demos.php
Author(s): DoITPoMS, University of Cambridge

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